In orthodontics, various devices are used for implementing tooth movement. Brackets are bonded to each tooth and forces and couples are applied to the teeth by archwires and elastic devices such as rubber bands. An important element in these devices is the ligature, which holds the bracket in contact with the archwire.
There are three types of ligatures that are currently used. The first is wire which is twisted around the bracket and archwire and cut with snips. The sharp ends and the time consumed during installation are problems, but the retention force is very high. The second type of ligature is a small o-ring that is difficult to install even with special tools. While these o-ring ligatures are most commonly used, their retention force is low. A third type of ligature uses braided elastomeric thread and extruded tubing which is tied to the various devices with knots.
Each of the above ligatures requires a great deal of time to install. Accordingly, a continuing need exists for ligatures which are easier to apply and which provide holding power which is equivalent to or better than previously available devices. A further need exists for improved ligatures to provide tensile forces between teeth.